Touch panels having a piezoelectric material have been proposed. When the piezoelectric material is pressed, the piezoelectric material generates a voltage corresponding to the change in strain with time during pressing. PTL 1 discloses a touch panel having a piezoelectric material, which can detect not only a touch position, but also press pressure (i.e., the strength of pressing) applied to the touch panel, by taking advantage of the above characteristics. Moreover, the use of a pyroelectric material, which has a relatively high piezoelectric constant, as the piezoelectric material can increase the sensitivity of detecting press pressure.